Non-over-1 temperament

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Revision as of 14:19, 7 February 2021 by Inthar (talk | contribs) (Sensi: shouldn't bold this)
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A non-over-2 temperament or non-over-1 temperament, is a regular temperament that tempers a subgroup corresponding to a harmonic series chord r:n1:...:nk where r ≠ 2, but is not meant to approximate a chord of the form 1:m1:...:mk. Non-over-2 temperaments give regular-temperament interpretations to edos that approximate over-2 chords such as 4:5:6:7:11 poorly, such as 14edo, 18edo, 23edo and 29edo.

Examples

Tridec

Tridec is a temperament generated by a generator near 455.2178¢ (for example, 11\29 or 14\37) and has an 8-note MOS. If you restrict to the 8-note MOS, Tridec is an 2.7/5.11/5.13/5 temperament that tempers the chord 5:7:11:13; one generator represents a 13/10, three generators represent a 11/10, -4 generators represent a 7/5.

Tridec essentially contains all the notes of 2.3.5 porcupine temperament and satisfies all its relations; hence it is essentially the same as 13-limit Ammonite; however, provided you restrict yourself to the 8-note MOS, you're using it as a non-over-2 temperament.

Sensi

Sensi is effectively a non-over-2 temperament provided you restrict yourself to the sensi[8] MOS. The sensi[8] MOS only has a 5:6:7:9:13 chord, but no chord of the form 2:m1:...:mk (except 2:3). Thus sensi can be viewed as a 2.6/5.7/5.9/5.13/10 or 2.3.6/5.7/5.13/10 temperament. (See x31eq data page.)

Generators Cents* Approximate ratios
0 0.000 1/1
1 443.322 13/10~9/7
2 886.644 42/25~5/3
3 129.966 13/12~14/13~15/14~27/25
4 573.288 7/5~25/18~18/13
5 1016.610 9/5~70/39
6 259.932 7/6~15/13
7 703.253 3/2
* in 2.3.5.7.13 POTE tuning
2.3.5.7.13 ratio interpretations